PITTSBURGH (KDKA) — A retired judge admitted to buying an AR-15 for his boyfriend, a convicted felon who authorities say had a Nazi obsession.

Karl Alexander pleaded guilty in federal court on Friday.

Alexander wrote on an official form that he was buying the gun for himself.

But he really bought it for Dennis Riggs, a convicted felon.

His home was raided last month by officials.

According to the criminal complaint, on Jan. 22, FBI Special Agents and Task Force Officers executed a federal search warrant at Riggs’ home in Troy Hill.

During the search, law enforcement located seven firearms: a Ruger .223 Caliber AR-15 style rifle; a Ruger .22 caliber revolver; a Harrington & Richardson shotgun; a .38 special revolver; a Colt .38 Caliber revolver; a US revolver, 32 Caliber, which was loaded with the hammer cocked; and a Harrington & Richardson shotgun.

Agents also located multiple rounds of ammunition in the residence. Riggs is prohibited from possessing a firearm because he was convicted on March 30, 1994, of aggravated assault.

Agents found on his phone a video depicting Riggs wearing Nazi apparel, offering Nazi salutes and loading and unloading an AR-15 style rifle.

They also found a video of the 2019 Christchurch and New Zealand mosque shootings which killed 51, images of the defendant with firearms and a photograph of Dylann Roof with his current Bureau of Prisons contact information.

Roof was convicted in the 2015 massacre at Emanuel African Methodist Episcopal Church in Charleston, South Carolina.

Riggs decorated his house with Nazi and Hitler posters and pictures, possessed numerous other weapons, knives and daggers, and had hundreds of bottles of liquor and alcohol.